Tin sponge article of manufacture and method of producing and utilizing the same



Sept. 4, 1923. 1,465.83?

E. KARDQS TIN SPONGE ARTICLE OF MANUFACTURE AND METHOD OF PRODUCING ANDUTILIZING" THE SAME Filed Dec. 27. 1919 INVENTOR B7 c g \|\\M msATTORNEY Patented Sept. 4, 1923.

EMAN'U'EL KARDOS, OF NEWARK, NEW JERSEY, ASSIGNOR TO METAL & THERMITCORPORATION, OF CHROME, NEW JERSEY, A CORPORATION OF NEW JERSEY.

TIN SPONGE ARTICLE OF MANUFACTURE AND METHOD OF PRODUCING ,AND

UTILIZING THESAME.

Application filed December 27, 1919; Serial No. 347,753.

To all whom it may concern:

Be it known that I, EMANUEL Kenoos, a citizen of Hungary and resident ofNewark, in the county of Essex and State of New Jersey, have inventedcertain new and useful Tin Sponge Articles of Manufacture and Methods ofProducing and Utilizing the Same, of which the following isaspecification.

The invention relates to the protection of tin sponge against theeffects of oxidation, and to this end comprises a novel article ofmanufacture and the method of producing and utilizing the same, bycoating or impregnating tin sponge with chloride of zinc, and,preferably compressing the tin sponge so treated into briquette form,and ultimately recovering the tin in solid form and substantial purityby. melting the admire ture at a temperature approximating the meltingpoint. of the tin and below the boiling point of the zinc chloride, andfinally separately withdrawing the molten tin and zinc chloride.

in the past the operation of melting tin sponge has been diflicult,expensive and wasteful of tin, because of the large surface which thesponge ofiers to contact with the air, which results in rapid oxidationof the tin even when the sponge has been hydraulically compressed. Infact, in order to melt the sponge without serious loss due to oxidation,it has been found necessary to efiect the melting operation underconditions of total exclusion of air,-and usually with the employmentof. reducing agents such as carbon and the like, which is effective toreduce any tin oxide which may be formed or which maybe present. Thislatter operation, however, can be carried out successfully only at ahigh temperature, and

with the concurrent formation of slag,

of the objections and dificulties aforesaidare eliminated and itispossible to prepare the tin sponge so that the same may be keptindefinitely without danger of impairment by oxidation or deterioration,and when 1t is desired to recover the tin in merchantable form thecomposite body of tin sponge and impregnating zinc chloride may bereadily melted at. a relativelyllowv zinc chloride may be efi'epted invarious ways, as by dipping the sponge in a solution of the chloride,spraying the spon e with the solution, or \by mixing and agitating thesponge and the solution in a suitable receptacle until the solutionpermeates the sponge and covers the surfaces of the latter. Preferablvthe impregnated or coated sponge is compressed into briquettes ofsuitable size which facilitates the handling and storage of individualbodies of sponge and also removes any excessive liquid. When it isdesired to recover the tin and also the impregnating zinc chloride thebodies or briquettes of impregnated tin sponge'are placed in a suitablevessel, preferably an open steel kettle, and heated to a temperature ofapproximately which temperature both the tin and, the.

chloride of zinc melts. The chloride of zinc,

being of lower specific gravity. than the tin, will float on top of themolten tin and protect the latter completely against the oxidizingeffect of the air. The water associated with the zinc chloride willevaporate,

but the chloride of zinc will be left intact, provided the temperatureis not raised above 230 C. at

the boiling point of the salt, viz: 262 C.

After the first batch hasbeen melted the impregnated briquettes orbodies 1 of tin sponge and chloride of zinc may be added from time totime, and as the briquettes or bodies have a lower specific weight thanmetallic tin but a higher one than the zinc chloride they will beentirely submerged in the molten zinc chloride and thus be pro tectedagainst any oxidizingefiect. The

derB zinc chloride may be ladled ofi or otherwise withdrawn'from time totime in a fused state and may be used again for treating furtherquantities of tin spon e, and any metal parholes of tin entrappe in thesame may be subsequently recovered. Likewise the molten tin ma bewithdrawn by any suitable means and allowed to cool, preferably underconditions which will reduce superficial oxi dation to a minimum.

A simple and effective form of apparatus for carrying out the operationaforesaid is ustrated in the accompanying drawing, in which A representsa metallic kettle or receptacle having an overflow spout C. Centrallymounted within the kettle A and passing through the cover thereof, is ametallic cylinrovided with anoverflow spout D, said cy inder beingpreferably open at the bottom and rovided with lateral peripheralorifices to allbw the molten metal to flow into the kettle A. The upperportionof the cylinder B is provided with splash plates E, E,-

and with a thermometer F. 'WhlCh dips into the molten zinc chloride andaffords a ready check on the temperature of the molten bath. Theapparatus as described may be fired b gas, oil or any other suitablemeans whic is capable of ready regulation to maintain a B through theopening in the top thereof bethe desired temperature, slightly in excessof that required to melt the tin, as hereinbefore described.

The tin sponge coated or. im regnated with chloride of zinc, and preerably in briquette form, is charged into the cylinder tween the splashplates E, E, and heat applied to the kettle A sufiicient to melt thetin,

I but below the boiling point of zinc chloride.

. ride.

The molten tin sinks to the bottom of the cylinder B and then passes outinto the kettle A where it accumulates until it overflows at spout C.The molten zinc chloride, however, being of li hter specific gravit thanthe molten tin, oats on the latter and is retained in the cylinder B, asindicated, so that when additional quantities of im regnated tin spongeare charged into the apparatus through the top of cylinder B they arecompletely submerged in the molten zinc chlo- As indicated, as themolten zinc chloride accumulates the excess overflows the entrance ofspout D and is discharged from the ratus. v

he principal object of treating the tin sponge with zinc chloride is toprevent 0x1- dation of the metallic sponge before and dur mg the processof melting, but especially be- 1. The method of'protecting tin spongewhich comprises coating the same with chloride of 'zinc.

2. The method of protecting tin sponge which com rises impregnatin andcoating the same with a solution of chloride of zinc.

3. The-method of rotecting tin spon against oxidation during the meltingoft e same which consists in impregnating the sponge with chloride of.zinc, and heatl the sameto a temperature below the boiling point of thechloride of zinc.

'4. The method of protecting tin sponge against oxidation during themelting of the same which consists in impregnating the sponge withchloride of zinc, compressing the mixture into bri uettes, and heatingthe briquettes in a suita le vessel to a temperature approximating thatof the melting-point of the tin.

5. The method of protecting tin sponge against oxidation during themeltin of the same which consists in impregnating the sponge withchloride of zinc, compressing the mixture into briquettes, heating thebriquettes in a suitable vessel to a temperature approximating that ofthe melting point of the tin, and separately withdrawing the molten tinand zinc chloride.

6. An article of manufacture comprisin a body of tin sponge coated withchloride 0 ZIIIC.

7. An article of manufacture comprisin a compressed body of tin spongecoated with chloride of zinc.

8. An article of manufacture comprising an admixture of tin sponge andchloride of zinc compressed into briquette form.

Signed at Chrome in the county of Middlesex and State of New Jersey this18th day of December A. D. 1919.

EMANUEL KARDOS.

begins and also. to I of the metallic tin, as.

as the impregnating zinc

